Artificial tooth



- y 1932- J. F. CALDWELL 9,0

ARTIFICIAL TOOTH Filed Dec. 19, 1930 INVENTOR. Job)? 2" Caldwe,

BY WM A TTORNEY.

Patented July 26, 1932 JOHN F. CALDWELL, OF HOUSTON, TEXAS ARTIFICIAL TOOTH Application filed December 19, 1930. Serial No. 503,580.

My invention relates to improvements in artificial teeth, adapted to be anchored to bridge work, or the like.

The invention may be embodied in an it anterior or posterior tooth. The tooth embodies a porcelain tooth element, and a metal backing element, connected by means so constructed that these parts are held together mechanically by frictional engagement and,

10 in addition, by cement, producing a unlon f the maximum strength. 7

In accordance with my invention, the metal backing element is provided with an expansible anchor pin, adapted for insertion 35 within a recess formed in the porcelain tooth element. The expansible anchor, pin has frictional engagement with the walls of the recess, and, in. addition to this frlctional engagement, the parts are held together by cement. The anchor pin is, preferably, rendered eXpansible by means of slotting the same, providing prongs, one of which is somewhat resilient, and may be suitably spread.

In the accompanying drawing, forming :a

part of this specification, and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is a front elevation of an artificial tooth embodying my invention,

Figure '2 is a central, vertical, longitudinal section through the same, parts in elevation, and separated, V

s Figure 2 is a similar view, parts assembled.

Figure 3 is a plan View of the same, Figure 4: is a side elevation of the same,

Figure 5 is a side elevation of the tooth ele-.

ment and backing element,

Figure 6 is a front perspective View of the 9 backingelement, Figure 7 is a rear perspective view of the backing element,

Figure 8 is a perspective view of the porcelain tooth element,

Figure .9 is a central vertical longitudinal section through an artificial tooth embodying a modified form of the invention, parts in elevation.

Figure 10 is a similar view showing a 5 further modification.

Figure 11 is a similar view showing a further modification,

Figure 12 is a perspective view of a modified form of backing element, showing the anchor pin and brace web slotted.

Figure 13 is a transverse section taken on line 13-13 of Figure 12. V

In the drawing, wherein for the purpose of illustration is shown a preferred embodiment of my invention, the numeral 10 designates a tooth element, formed of glazed por celain, or like material. This tooth element embodies a body portion 11, having the curvature or shape of a natural tooth, and a root portion 12, integral therewith. The body portion 11 has a lingual fiat face 13, and the root portion projects lingually beyond the fiat face 13, for a substantial distance, providing a fiat straight shoulder or face 14:, arranged at substantially a right angle to the face 13. The root portion 12 may have its end surface 15 ground to correspond to the curvature of the gum or tissue which it engages. It is illustrated as ground concave, but it may be ground convex for producing'a cone. The tooth elements are made in various stand ard shapes and sizes, and each tooth element may have its root portion and incisal portion ground down for a fine fitting. This is rendered possible by the arrangement of the anchor means, as will be described. The backing element which is formed of metal, such as gold or the like, embodies a backing plate 16, which is fiat and is adapted to engage with the flat face 13, of the body portion of the tooth element. This backing plate 16 extends from the shoulder or face 14 to the incisal portion or bite 17, of the porcelain tooth element, and, preferably, projects slightly beyond the bite whereby the strains resulting from mastication are car.- ried principally by the backing. Formed integral with the inner end of the backing plate 16 is a lateral extension 18, preferably arranged app oximat y a a ghtangle thereto and disposed to engage the shoulder or face 1 1, and being co extensive in size with the-same, and corresponding in shape thereto. The back ings would be manufactured in various lengths and Widths to correspond to the clined bottom wall 241-, as shown. has a width less than the diameter of the tooth elements with which they are to be used.

The numeral 19, Figures 1 to 8, inclusive, designates an anchor pin, having a substantially triangular web 20, preferably formed integral therewith. This anchor pin and web are disposed upon the outer side of the backing plate 16, and are rigidly attached thereto, by solder, or the like, and are also disposed at the central longitudinal axis of the backing plate, and adjacent to the lateral extenslon 13. The anchor pin 19 is adapted for 1nser tion within an opening or recess 21, which is formed in the body portion 11 of the tooth element and extends through the lingual face 13. and terminates at a point 22, spaced from the outer face of the body portion. The body portion is also provided with a slot 23, leading into the recess 21, and this slot has an in- The slot opening 21, and this slot is triangular and of a size to receive the reinforcing web 20. The opening or recess 21 is, preferably, circular in cross-section, and preferably tapers or decreases in diameter toward the flat lingual face 13, producing an undercut engagement with the anchor pin, as will be explained. The anchor pin 19 is, preferably, cylindrical, and is expansible, and is, preferably, rendered expansible by providing the same with a longitudinal slot 25, affording prongs or tines 26. One or both of these tines may be provided with transverse notches 27. One tine 26 is resilient, while the other tine is held rigid by the web 20.

In assembling the elements of the tooth, as shown in Figures 1 to 8, inclusive, the anchor pin 19 has its resilienttine 26 bent or spread outwardly from the rigid tine, so

that the pin tapers or increases in diameter forwardly from the lingual side of the backing plate 16. This is the condition before insertion within the recess. These tines 26 are spread sufliciently so that they have to be somewhat compressed when being inserted into the opening or recess 21, and the compression is effected or aided by one tine engaging the inclined bottom wall 24. When the tines enter the recess 21, the resilient tine springs from the rigid tine, and both tines have firm frictional engagement with the side wall of the recess 21, such wall tapering toward the lingual face 13, as stated.

It is, thus, seen that the expansible pin will have positive frictional engagement with the wall of the recess 21. The web enters the slot 23. In addition to this frictional engagement, the pin 19 and, web 20 are secured to the porcelain tooth element by means of cement, arranged within the recess 21 and slot 23. This cement will enter the slot of the anchor pin, filling the same,

' and when the cement hardens, it will rigidly hold the tines against radial collapsing movement. It is, thus, seen that a connection has been eifected between the porcelain tooth element and the metal backing, embodying both a mechanical frictional engagement and a cement union, whereby the maximum strength and durability is obtainable. The plate 16 and extension 18 are secured to the adjacent faces of the porcelain tooth element by cement, and the anchor pin 19 and web 20 are, therefore, completely enclosed and protected from the action of saliva.

In Figure 9, I have shown a slight modification of the invention, wherein the slot 23 is provided with an abrupt horizontal shoulder 28, to engage with a corresponding shoulder 29, formed upon the web 20. All other parts remain identical with those shown and described in connection with the first form of the invention.

In Figure 10, I have shown a further modification, wherein the slot 23 is equipped with a shoulder 30, and a recess or notch 31, at the forward end of the shoulder. The web 22 has ashoulder 32 to engage the shoulder 30, and an extension 33 to enter the recess 31. All other parts remain identical with the first form of the invention.

In Figure 11, I have shown a further modification, wherein the slot 22 is omitted, and a separate opening or recess 34 is provided in the porcelain tooth element, receiving a pin or lug 35, rigidly attached to the backing plate 16, and separate from the anchor pin 19. All other parts remain identical with the first form of the invention, and the several engaging parts are connected by cement.

In Figures 12v and 13, I have shown a further modification of the invention, which is similar to that shown in Figure 1, except that both the anchor pin 19, and web 22, are rendered radially or laterally expansible by means of a slot 36, passing through the same. The spaced sides of these elements are spread sufliciently so that they will have a Width greater than that of the recess 21 and the slot 22, whereby they must be compressed before entering the same and, upon being released, will spring outwardly for firm frictional engagement therewith.

In view of the foregoing description, it is thought that the construction and use of the several forms of the invention has been made clear.

It is to be understood that the forms of my invention herein shown and described are to be taken as preferred examples of the same, and that various changes in the shape, size and arrangement of parts may be resorted to without departing from the spirit of my invention, or the scope of the subjoined claim.

Having described my invention, what I claim is An artificial tooth comprising a porcelain tooth element having a transverse recess and a longitudinal slot leading into one side of the recess, said recess increasing in diameter toward its closed end, a metal backing plate for the tooth element, an anchor pin fixedly secured to the backing plate and embodying a pair of substantially straight relatively stout spaced tines which diverge throughout their entire length toward their free ends whereby the space between the tines flares toward its free end, the flaring arrangement being maintained during the insertion of the pin into the recess, and a web rigidly secured to one tine and to the backing plate and extending longitudinally of the backing plate, the remaining tine being resilient, the arrangement being such that the tines are adapted for insertion within the transverse recess and the web for insertion within the slot, the ends of the diverging tines having clamping engagement with the walls of the transverse recess, and the forwardly flaring space between the tines being adapted to be completely filled with the cement. In testimony whereof I aflix my signature.

JOHN F. CALDWELL. 

